Nicotinic acid and picolinic acid derived near-infrared fluorophores

Abstract

This invention relates to new fluorescent chemical entities, including fluorescent molecules that comprise a carboxyl or carbonyl functionalized pyridine moiety. This invention also relates to the corresponding reactive versions of such molecules. This invention also relates to the corresponding conjugates with moieties such as peptides, proteins, various biomolecules, carbocyclic and heterocyclic compounds, sugars, and their uses thereof.

What is claimed is: 
     
       1. A method of in vivo optical imaging, the method comprising:
 (a) administering to a subject a biocompatible fluorescent molecule comprising one or more biomolecules covalently linked to a fluorescent compound represented by formula (2): 
 
       
         
           
           
               
               
           
         
         or a salt thereof, wherein:
 X is independently selected from the group consisting of C(CH 2 Y 1 )(CH 2 Y 2 ), O, S, and Se; 
 Y 1  and Y 2  are independently selected from the group consisting of H, C 1 -C 20  aliphatic group and a C 1 -C 20  aliphatic group wherein one or more methylene groups are replaced by O, S, or NH; 
 W represents a benzo-condensed ring or a naphtho-condensed ring; 
 R 1  is selected from the group consisting of H, (CH 2 ) x CH 3 , (CH 2 ) n SO 3   −  and (CH 2 ) n SO 3 H, wherein x is an integer selected from 0 to 6 and n is an integer selected from 2 to 6; 
 R 4  is selected from the group consisting of H, (CH 2 ) x CH 3 , (CH 2 ) n SO 3   −  and (CH 2 ) n SO 3 H, wherein x is an integer selected from 0 to 6 and n is an integer selected from 2 to 6; 
 R 2  and R 3  are independently selected from the group consisting of H, carboxylate, carboxylic acid, carboxylic ester, amine, amide, sulfonamide, hydroxyl, alkoxyl, a sulphonic acid moiety and a sulphonate moiety; 
 Q is a heteroaryl ring substituted with —CO 2 H, —C(O)-halide, —C(O)O-benzotriazolyl, —C(O)O—N-succinimidyl, —C(O)O-tetrafluorophenyl, —C(O)O-pentafluorophenyl, —C(O)O-imidazolyl, or —C(O)O-p-nitrophenyl; or 
 Q is selected from the group consisting of 
 
       
       
         
           
           
               
               
           
         
         
           Q is a 6-membered heteroaryl ring substituted with —C(═O)R**, wherein R** is a saturated straight-chain hydrocarbon, a branched hydrocarbon, or a cyclic hydrocarbon; or 
           Q is a carboxyl or carbonyl substituted 6-membered heteroaryl ring selected from the group consisting of pyridine, pyrimidone, pyrazine and pyridazine; and 
           wherein the biomolecule is chemically linked to the fluorescent compound via reaction with Q thereby producing the biocompatible fluorescent molecule; 
         
         (b) allowing time for the biocompatible fluorescent molecule to distribute within the subject or to contact or interact with a biological target within the subject; 
         (c) illuminating the subject with light of a wavelength absorbable by the biocompatible fluorescent molecule; and 
         (d) detecting the optical signal emitted by the biocompatible fluorescent molecule. 
       
     
     
       2. The method of  claim 1 , wherein the signal emitted by the biocompatible fluorescent molecule is used to construct an image. 
     
     
       3. The method of  claim 2 , wherein steps (a)-(d) are repeated at predetermined intervals thereby allowing for evaluation of the emitted signals of the biocompatible fluorescent molecule in the subject over time. 
     
     
       4. The method of  claim 3 , wherein the subject is an animal or human. 
     
     
       5. The method of  claim 4 , wherein in step (a) two or more biocompatible fluorescent molecules whose signal properties are distinguishable are administered to a subject. 
     
     
       6. The method of  claim 5 , wherein the illuminating and detecting steps are performed using an endoscope, catheter, tomographic system, hand-held optical imaging system, surgical goggles, or intra-operative microscope. 
     
     
       7. The method of  claim 6 , wherein the presence, absence, or level of signal emitted by the biocompatible fluorescent molecule is indicative of a disease state. 
     
     
       8. The method of  claim 7 , wherein the method is used to detect and monitor disease. 
     
     
       9. The method of  claim 8 , wherein the disease is selected from the group consisting of cancer, cardiovascular diseases, neurodegenerative diseases, immunologic diseases, autoimmune diseases, respiratory diseases, metabolic diseases, inherited diseases, infectious diseases, bone diseases, and environmental diseases. 
     
     
       10. The method of  claim 9 , wherein prior to step (a) the fluorescent compound of  claim 1  is mixed with cells to label the cells and the resulting labeled cells are administered to the subject in step (a). 
     
     
       11. The method of  claim 10 , wherein the signal emitted by the biocompatible fluorescent molecule is used for monitoring trafficking and localization of cells or evaluation a cell therapy. 
     
     
       12. The method of  claim 1 , wherein the fluorescent compound has an absorption maxima and an emission maxima between about 500 nm and about 900 nm. 
     
     
       13. The method of  claim 12 , wherein the fluorescent compound has an absorption maxima and an emission maxima between about 600 nm and 800 nm. 
     
     
       14. The method of  claim 1 , wherein the biocompatible fluorescent molecule becomes activated upon interaction with the biological target. 
     
     
       15. The method of  claim 1 , wherein the biocompatible fluorescent molecule has a high binding affinity to the biological target. 
     
     
       16. The method of  claim 1 , wherein the biomolecule is a cell. 
     
     
       17. The method of  claim 1 , wherein R 1  is selected from the group consisting of (CH 2 ) x CH 3 , (CH 2 ) n SO 3   −  and (CH 2 ) n SO 3 H, wherein x is an integer selected from 0 to 6 and n is an integer selected from 2 to 6. 
     
     
       18. The method of  claim 1 , wherein Q is selected from the group consisting of carboxyl substituted pyridine, pyrimidone, pyrazine, and pyridazine. 
     
     
       19. The method of  claim 1 , wherein Q is carboxyl substituted pyridine. 
     
     
       20. The method of  claim 1 , wherein Q is selected from the group consisting of isonicotinic acid, nicotinic acid and picolinic acid. 
     
     
       21. The method of  claim 1 , wherein Q is represented by a structural formula selected from the group consisting of: 
       
         
           
           
               
               
           
         
       
     
     
       22. The method of  claim 1 , wherein at least one of the moieties R 1  to R 3  is, or contains a sulphonic acid moiety or a sulphonate moiety. 
     
     
       23. The method of  claim 1 , wherein R 1  and R 4  are independently —H, (CH 2 ) n SO 3   −  or (CH 2 ) n SO 3 H. 
     
     
       24. The method of  claim 1 , wherein the fluorescent compound of formula (2) is: 
       
         
           
           
               
               
           
         
       
     
     
       25. The method of  claim 1 , wherein the fluorescent compound of formula (2) is: 
       
         
           
           
               
               
           
         
       
     
     
       26. The method of  claim 1 , wherein Q is represented by a structural formula selected from the group consisting of: 
       
         
           
           
               
               
           
         
       
     
     
       27. The method of  claim 1 , wherein in step (a) said administration is topical administration.